feature: kit publish

[barraguda]

Is your feature request related to a problem? Please describe.
When deploying apps to the app_store, there are a couple pitfalls that a developer can fall in: hash mismatch, mirrors, publisher not being the nodes address.

Describe the solution you'd like
kit publish

Notes
Private key can live in .env or be passed in. Can autofill hashes by doing a `kit s´ if no latest metadata hash is filled in.

[nick1udwig]

As discussed in the chat -- I'm pretty wary of putting private keys in .env. I think its acceptable short-term if we have a plan to:

1. Delegate, as, I believe dolled-possum suggested, so users don't have to put keys holding $ in .env,
2. Some other more secure method that doesn't involve writing private keys in plaintext.